An unmanned robot used onboard senors to measure oxygen consumption from the bottom of Mariana Trench in 2010
The Mariana trench sits seven miles below sea level in the Pacific
But it turns out organisms can thrive at this incredible depth, according to a new study published Sunday, March 17, in the journal Nature Geoscience.
Sediment tested in the deep ocean trench revealed that it contains almost 10 times more bacteria than the sediments at a shallower, nearby site that's about 4 miles deep.
This is unexpected since the farther down you go, the less food you expect to find.
The microbes are able to survive on the remains of dead animals, algae and other microbes that float down the trench slopes, making it a surprisingly rich place for organic matter, scientists learned.
Scientists used an unmanned robot to measure the distribution of oxygen in trench sediment in 2010. Sensors onboard the robot were inserted directly into the seabed since samples can't be brought back to the surface because the microorganisms might die due to extreme changes in temperature and pressure.
In 2012, director James Cameron became the first person to visit the bottom of the trench in more than 50 years. Footage from the deep-sea dive showed a few new species, but it's still a rather barren environment.
Videos from the bottom of the Mariana Trench confirm that "there are very few large animals at these depths," lead researcher Ronnie Glud from the University of Southern Denmark said in a statement. "Rather, we find a world dominated by microbes that are adapted to function effectively under conditions too inhospitable for most higher organisms.”